This contractor will be a clinical center for the collaborative clinical trial, Post-CABG (Coronary Artery Bypass Graft) Study. The primary objective is to see if lowering serum cholesterol by drug treatment or by lifestyle modification (dietary, exercise, and cessation of smoking) will have a beneficial effect on the rate of long-term (after 1 year) graft reocclusion. Post-CABG will be a randomized clinical trial which will also have a biobehavioral component and an epidemiologic study component. The objective of the biobehavioral study component is to identify the biobehavioral and psychosocial factors that contribute to the successful adjustment after CABG. The objective of the epidemiologic study component is to identify clinical, biochemical and hemostatic factors that correlate with native coronary atherosclerosis and graft occlusion. Subsidiary objectives of the trial include assessing the effects of interventions on (1) progression of coronary atherosclerosis in the native vessels and internal mammary grafts; (2) ventricular function; (3) morbidity and (4) quality of life.